Method of cold flanging irregularly shaped sheet-metal plates



July 8 1924; 1,501,008

H. M CABE METHOD OF GOLD FLANGING IRREGULARLY SHAPED SHEET METAL PLATES k Filed July 31, 1922 2012/2665: /0 v e E Patented July 8, 1924.

LINED-STATES PATENT FF1cE.

HUGH MCCABE, O F LAWRENCE, MASSACHUSETTS. i

To aZZ whom it may concern Be it known that I, HUGH McCABn, a

citizen of the 'United States, residing at Lawrence, in the county of Essex and State of Massachusetts, have invented certain new and useful Improvements in Methods of Cold 'Flanging Irregularly Shaped Sheet- Metal Plates; and I-do hereby declare the following to bela'full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use thesame.

The present invention relates to an improvedmethod of cold flanging irregularly shaped sheet metal plates.

The machine of the McGabe Patent No. 1,006,861, was intended for use, among other, things, in flanging circular disks, but the" bender face and the cooperating faceagainst which the flange is formed were required to correspond to the curvature which it was desired vto give to ,the flange. VViththe bender face and cooperating face curved, it is apparent that any given pair of such faceswould be adapted only for a single radius, of curvature, and while the use of such machine for such purpose accomplished a very substantial saving over the hot flanging of metal plates, the fianging of irregu larly shaped plates, such, for ena'mplefas the tube sheet of a locomotive fire box, presented a pieceof work to which the machine T of such patent was notadapted.

In the McCabe- Patent N' 464,732, the flanging of square corner and filetedcorner" plates'was contemplated by theuse of forms V which fitted the corners, butit was required that the metal be heated in order to do the workat thecorners; f

The object of the present" invention is to produce a method of cold *flanging sheet metal plates without the usejof' formers espieciallyishaped to the' surfaces to be produced and adapted tofforin flanges 'on a'wide variety "of irregularly shaped plates. To

the above end the present invention consists in the methodjhereinafterdescribed and par-Q A r short radius portions C of the tube sheet tic'ularly' defined in the claims. v

In'the accompanyingdrawing; Figure 1 is an'el evationand Fig Q is an edge view of 'a firec-box tube sheet for flocomotive boilers and Fig. is a sectional plan offa 1 portion of a McCabe coldjflanging machine" arranged to ractice the ,method herein} described.

Application filed ifuly 31, 1922. Seriatlv'o. $78,590:,

The present invention as employed in isre-entrant at E, which is the lower part of the ogee, and salientthroughout the remainder F of the ogee and throughout the short radius and'long radius portions. Now, the method is such that it will form the flange on the straight, salient and re-entrant portions of the edge within certain limits without any change in the formers. The work is clamped between upper and lower clamp members 9 and 10. The lower clamp member 10 is a'face against which the flange is to be formed, having a radius of curvature corresponding to or less than the radius of curvature of the salient curvature of shortest} radius, and a bender 11 provided with a convex flange forming face of a radius of curvature corresponding to or less thanthe radius of curvature of the re-entrantcurvature of shortest radius of the flange to, be'

sheet illustrated, would be the salient curva ture F, and the'curvature of the flange form ing'face 'of thef bender 11 corresponds to or f is less than the radius of curvature ofgth re -entrant portions of" the flange 'to be formed, 'which, in the tube sheet illustrated," would be the re-entrantportions {Furf thermore, the 'face of the bender is made narrow so that shortf port ions of the flange may be operated u on 'at eachbending operation; The clamp is {closed on the body portionfoffthe 'plate'to be flanged adjacent to the flange portion, i; e.,- the portion to be formed into the flange, and while'so clamped the adjacent flange portion is'operatedupon lOO by the bender toform it into afflange. The Y 1 according tothe'present method, and then the machinewillbeprovided with a different] i pair of formers and the short radius nor tions of the flange will be formed, This will be done by providing the machine with a former 10 of shorter radius of convex curvature, which will project further into the flange receiving space of the machine, and by using a bender 11 provided with a face correspondingly shorter, that is, extended a correspondingly shorter distance from the bender segment 12.

In carrying out the invention in its best form the bender 11 will be provided with a sliding bender face 13 which, when it engages the flange. portion of the sheet, will remain in contact with the portion which it first engages, and slide in the bender 11 so as thereby to prevent the wiping of the-bender face over the surface of the flange being formed. This is a feature of the invention viewed in its more specific aspects.

Another feature which contributes to most perfect form of the invention consists in making the bender face narrower than the face against which the flange is formed.

This permits the formation of re-entrantly curved flanges of shorter radius of curvature than would otherwise be possible.

In practicing the present method the fla nging machine will be provided with two formers, of which the clamp member 1.0 is one and the bender 11 is the other. The

former 10 will have a radius of curvature corresponding to or shorter than the radius of curvature of the flange to be formed at its point of salient curvature of shortest radius, and the benderwill havea radius of curvature corresponding to or less than the radius of curvature of the flange to be formed at its point of re-entrant curvature of shortest radius. r

The method will be practiced as follows: Starting at one end of the flange, as at the end 14-, the operator will proceed to form partial bends in the flange, working along the edge up to the beginning 15 of the portion C of short radius of curvature. This portion will be passed,-and the forming of the flange on the next portion D of the plate will he proceeded with, after which the short radius portion C will be passed, andthe remainder of the edge of the plate will be operated upone These operations will be continued untilthe straight, ogee and long radius portionsof theflangefare formed, after which the plate will be finished at the short radius portions.

The part of the bodyportion of the plate which is subjected to theclamping action so as to hold it during the formation or partial formation of the flange is shown in F 3, and is indicated by the outline of the lower clamping member 10. It is immaterial, of course, what the shape of the top clamp member may be, because the area effective for holding the plate is the area of thebottom=clamp member. -This area, it

Q will be observed, is, convex to the flange por-' which it is intended to assume inthe fin g ished work. In the final bend imparted to the flange it is pressed against the stationary former surface.

It will-be observed that in forming the straight portions A of the disk, the metal will be stretched and compressed along the edge of theflange as the forming proceeds, that in forming the re-entrant portions of the flange the metal of the edge of the plate will be compressed, and that in forming the curved portions the metal will be both stretched and compressed as the forming proceeds. Themethod is best carried out, by use of astraining device such as is shown in McCabe Patent No. 1,408,106, adjustments of the amount of strain to which the plate is subjected during the forming operation being made from time to time as the flanging progresses. Thus throughout the straight portions of the flange a cer tain adjustment of the amount'of strain to I employed which will be greater with short radlus'curves than with long radius curves.

Having thus described the invention, what is claimed is: g

1. Themethod of cold flanging irregularly shaped sheet metal plates having points of salient and re-entrant curvature, which consists in clamping the body portion of the plate adjacent to the flange portion between clamping members, and subjecting the flange portion of the plate to bendingpressure between two formers, one'of which is provided -with a convex face against which the flange'is to be formed, having a radius of curvature corresponding to or less than the radius ofcurvature of the flange at the point of salient curvature of shortesti radius, and the other of whichisprovided with a convex flange forming face of a ra dius'of curvature corresponding to or-less than the radius of curvature of the plate at the point of re-entrant curvature of, shortest radius. r V V 2'. The method of cold flanging irregularly shaped; sheet metal) plates having points of [re-entrant curvature, whichconsists in clamping successive parts of the body portion of the plate adjacent to the flange portion between clamping members, and subjecting the successive flange portions of the plate to the action of a narrow faced bender of convex form having a radius of curvature less than the radius of curvature of the plate at its point of re-entrant curvature of shortest radius.

3. The method of cold flanging irregularly shaped sheet metal plates, which consists in clamping successive areas of the body portion of the plate of convex form located tangent to the flange portion at the flange forming point, and subjecting the flange portion of the plate at such point to the bending action of a former which presents a convex face to the flange portion.

4. The method of cold flanging irregularly shaped sheet metal plates, which consists in clamping successive parts of the body portion of the plate over a convex area tangent to the flange forming point, and subjecting a part of the flange portion to the action of a convex bender at such point, and repeating such operations along.

the edge of the plate.

5. The method of cold flanging irregularly shaped sheet metal plates, which consists in clamping successive parts of the body portion of the plate over an area adjacent and convex' to the flange portion of the plate, and subjecting the flange portions opposite the clamped area to the bending action of a flange former.

6. The method of cold flanging irregularly shaped sheet metal plates, which consists in clamping successive parts of the body portion of a plate adjacent to the flange portion between clamping members over areas adjacent to, the flanged portion, and subjecting the adjacent flange portion sists in clamping a relatively small convex area of the body portion of the plate tangent to the flange portion, and subjecting the flange portion of the plate at such point of tangency to the bending action of a narrow convex flange forming bender.

8. The method of cold flanging irregularly shaped sheet metal plates, which consists in clamping a convex area of the body portionofthe plate adjacent to therflanged portion between clamping members, straining the plate, subjecting the plate to the ac-' tion of the bender for bending a portion of the flange at the point of tangency of the clamping area of the flanged portion, and

varying the straining for diflerent portions of the plate depending upon the direction and degreeof curvature. 9. The method of cold flanging irregularly shaped sheet metal plates, which consists in clamping the body portion of the sheet over a small area tangent and convex to the flange portion and forming the flange by the use of convex faced formers.

10. The method of cold flanging irregularly shaped sheet metal plates, which. consists in clamping successive convex areas of the body portion adjacent to the flange portion, and at each clamping operation subjecting the flange portion adjacent thereto to the flange forming action of a convex faced bender.

HUGH MoCABE. 

